People with bipolar I experience manic episodes, while people with bipolar II experience less severe hypomanic episodes. The two condition types have certain symptoms in common as well as similar symptom frequency.

People with bipolar disorder experience uncommon highs or lows in mood. During a “high,” also known as a manic episode, people feel intense energy or excitement.

During a “low” or depressive episode, they experience symptoms of depression, such as feeling down, excessive guilt, frequent tearfulness, and lack of interest in enjoyable activities.

There are four distinct types of bipolar disorder:

  • bipolar I disorder
  • bipolar II disorder
  • cyclothymic disorder, or cyclothymia
  • other specified and unspecified bipolar disorder

A doctor can diagnose a person with one of the above types based on the duration and intensity of their symptoms.

Bipolar I and bipolar II are the most widespread forms of bipolar disorder. They are also typically the more severe bipolar disorders, and they share many similar symptoms. However, they are distinct from one another.

In this article, learn about the similarities and differences between bipolar I and bipolar II. We also consider their causes, symptoms, and available treatment options.

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Bipolar I and II have similar symptoms and symptom patterns. However, people who have bipolar II typically experience less severe manic episodes than people with bipolar I.

Doctors refer to these less severe periods of mania as hypomania. These episodes must last for at least 4 days but no more than 7 days.

To receive a diagnosis of bipolar II, a person must experience cycles of hypomanic and depressive episodes without ever having a full manic episode.

By contrast, a doctor can diagnose bipolar I based on the presence of a manic episode alone. People with bipolar I disorder have at least one manic episode that persists for a week or longer or severe mania that requires hospitalization.

Those with bipolar II disorder do not generally require hospitalization during hypomanic periods. Doctors sometimes misdiagnose bipolar II as depression because the hypomanic symptoms can be very subtle. In addition, they may also misdiagnose periods of sudden joy as hypomania.

In between these episodes of mania and depression, people who have either of these types of bipolar may experience periods of stable mood. A person may also alternate between symptoms of depression and mania at the same time. This is known as bipolar with mixed features.

The main symptoms of bipolar I and bipolar II are mania, hypomania, and depression.


During a manic episode, people can experience:

  • intense enthusiasm, happiness, or excitement
  • anger, restlessness, or irritability
  • increased energy
  • less need for sleep and difficulty sleeping
  • racing thoughts
  • difficulty concentrating and making decisions
  • reckless behavior such as excessive substance use
  • excessive pleasure-seeking behaviors


In a state of hypomania, people experience symptoms similar to those in mania, except less severe.

Hypomania can still interfere with a person’s quality of life, and family and friends may notice that the person is experiencing mood changes.


People with bipolar disorder may experience depressive symptoms that are the same as those experienced in cases of clinical depression. These include:

  • low or depressed mood
  • hopelessness
  • low energy and fatigue
  • changes in sleeping patterns
  • changes in appetite
  • poor concentration
  • loss of interest in formerly enjoyable activities
  • low self-esteem
  • psychomotor agitation
  • thoughts of suicide or death
  • suicidal behavior

Doctors consider these symptoms a depressive episode if they persist for 2 weeks or more.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects if it’s safe to do so.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The 988 Suicide and Crisis Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.

Find more links and local resources.

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According to the National Institute of Mental Health (NIMH), approximately 2.8% of adults in the United States experience bipolar disorder in a given year. An estimated 4.4% of people experience bipolar disorder at some point in their lives.

The condition affects men and women almost equally for bipolar I, but rates in bipolar II appear to be slightly higher for women. Onset occurs at an average age of 25. However, it can happen to people of any age.

To receive a diagnosis of bipolar disorder, individuals will need to see a psychiatrist, psychologist, or supervised counselor. They will review the person’s medical history, symptoms, and may seek to exclude other potential causes.

This psychiatric assessment will focus on a person’s thoughts, feelings, and behaviors. They may also assess how other people respond to the individual in social situations.

The psychiatrist or psychologist may also ask a person to keep a mood diary to track their moods, sleep patterns, and other symptoms. This diary can help with a diagnosis.

The psychiatrist or psychologist will compare the person’s symptoms to the criteria for bipolar disorders outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

The psychiatrist or psychologist may carry out blood tests, a physical examination, or brain imaging tests to rule out other causes of the symptoms.

Treatment for bipolar I disorder and bipolar II disorder typically consists of medications, psychotherapy, and lifestyle changes.

As bipolar disorder is a long-term condition, treatment will be long lasting. Some people may have a treatment team that includes a psychologist, psychiatrist, therapist, and psychiatric nurse practitioner.


Doctors usually prescribe mood stabilizers, such as lithium, for bipolar disorder. They may also prescribe antipsychotic drugs for manic episodes and antidepressants for depression.

As antidepressant medications may trigger manic episodes in some people, doctors might recommend a combination of antidepressant and antipsychotic drugs to reduce depression while stabilizing mood.

For people with anxiety or sleep problems, anti-anxiety medications, such as benzodiazepines, may help. However, this strategy may come with a risk of dependence on benzodiazepines.

People can begin taking medications right away, even if they are not currently experiencing a manic or depressive episode.

It is vital to continue taking medications even during periods of stable mood to avoid relapse.


Psychotherapy can play a role in bipolar I and II treatment plans. Therapy may occur in person or remotely.

Several different types of therapy can help, including:

  • Interpersonal and social rhythm therapy (IPSRT): This focuses on establishing a structured routine to help people cope with symptoms.
  • Cognitive behavioral therapy (CBT): CBT helps people challenge negative thoughts and replace them with more realistic or objective ones. It can also increase a person’s awareness of their thoughts and emotional responses. This may help them track changes in mood, identify triggers, and recognize patterns of thoughts and emotions that might signal the onset of a manic or depressive episode, thus allowing them to prepare a plan to manage these symptoms.
  • Family-focused therapies: These therapies enhance communication with family members and to foster family support.

However, psychotherapy is not a frontline treatment for bipolar disorders, and there are many instances in which individuals can remain stable without it.

Lifestyle changes

Many people can make lifestyle changes to manage their symptoms and help stabilize their moods. Examples of helpful changes include:

  • avoiding alcohol and drugs
  • exercising regularly
  • eating a balanced diet
  • establishing a sleep routine
  • attending a support group for people with mood-related disorders
  • practicing mindfulness and meditation
  • reducing stress where possible
  • learning more about their condition

Some people also find it helpful to keep a daily mood diary. Keeping a journal can allow people to see patterns in their thoughts, moods, and behaviors.

A mood diary also helps identify triggers for manic or depressive episodes. This may help a person take appropriate action before a slight mood change worsens.

Although bipolar I and II are long-term conditions, most people can manage their symptoms with medications, therapy, and lifestyle changes.

Maintaining regular contact with mental health professionals and seeking support from friends and family can make it easier to cope with challenging symptoms.

Anyone who thinks they may be experiencing symptoms of bipolar I or II should speak with a doctor for a proper diagnosis.